Once a remote and frozen area, the Arctic has rapidly become a hotspot for global strategic and economic interest. As melting ice unlocks new shipping routes and new natural resources, the region’s importance has increased, drawing non-arctic states into the competition for influence and opportunity. China’s acceptance as an observer in 2013 marked a turning point in the region’s security dynamics, and have increased activities and engagement in the Arctic region ever since. Therefore, this thesis is investigating how the growing strategic interest from China has influenced the security dynamics in the Arctic region. Using the regional security complex theory as a theoretical lens, the study analyses Arctic security developments between 2001-2013 before China's observer status and between 2013-2024. It examines the influence of China’s observer status in the Arctic council on Arctic security dynamics, focusing on the essential structure from RSCT: boundary, polarity, social construction and anarchic structure. The comparative description of the Arctic region indicates an internal transformation with risk for external transformation through China’s attempt to renegotiate its status. Arctic security has shifted from a regional issue to a globalised security arena. The thesis highlights the need for a comprehensive approach that considers both traditional and non-traditional security elements when assessing Arctic security dynamics.